1. Technical Field
The present invention relates to a mount arrangement for a lens interchangeable type photographic camera which is capable of both automatic diaphragm control and automatic focusing and also relates to an interchangeable lens unit for the camera.
2. Prior Art
In recent lens interchangeable photographic cameras, various means are needed on and/or in the vicinity of mount members of a camera body and an interchangeable lens unit for transmission of mechanical and electrical signals between the camera body and the interchangeable lens unit with multiplication and improvement of camera functions. Particularly, in a lens interchangeable photographic camera which is adapted to effect automatic diaphragm control and automatic focusing by signals from the camera body, a diaphragm interlocked mechanism, an automatic focusing drive mechanism and electrical contact means for supplying and receiving various electrical signals are needed on and/or in the vicinity of the mount members of the camera body and the lens unit in addition to a positioning mechanism for positioning the lens unit relative to the camera body with the lens unit mounted on the camera body. Thus, the diaphragm interlocked mechanism, the automatic focusing drive mechanism and the electrical contact means are composed of a member or members provided on or in the vicinity of the mount member of the lens unit and a corresponding member or members provided on or in the vicinity of the mount member of the camera body, respectively. However, as there is not a large space permitting the provision of these members on and/or in the vicinity of the mount members without exposing these members to the outside of the camera body and the lens unit and without intercepting the optical path for photographing, it becomes necessary to determine the positions of these members rationally on the whole so that no interference occurs between the members on the side of the lens unit and the members on the side of the camera body upon the mounting and demounting of the lens unit on and from the camera body and so that the corresponding members are coupled with or brought into contact with one another without fault. Conventionally, a bayonet mount device which couples the lens unit with the camera body through a predetermined angle rotation of the lens unit relative to the camera body is used for the coupling, and therefore this must be also taken into consideration to determine the positions of those members on and/or in the vicinity of the mount members of the camera body and the lens unit.
Hitherto, a photographic camera of the above mentioned type capable of automatic diaphragm control and automatic focusing by signals from a camera body is known by Japanese magazine, the Nippon Camera, December 1982, page 280. With this camera, a positioning member is located at an upper and right side portion of the mount member of the camera body as viewed from the front of the camera body and urged radially inwardly to engage a positioning recess formed on a bayonet claw located at an upper left side portion of the amount member of the lens unit as viewed from the rear of the lens unit with the mounting of the lens unit on the camera body completed. A diaphragm control member to be coupled with a diaphragm interlocked member of the lens unit for automatic diaphragm control is located at the inner peripheral side of a lower-most portion of the mount member of the camera body with its end retreated from the mount surface of the mount member while the diaphragm interlocked member is located at the inner peripheral side of a lower-most portion of the mount member of the lens unit with its rear end projecting from the mount surface of the mount member. Electrical contacts of the camera body to be brought into contact with electrical contacts of the lens unit are located on the mount surface of the mount member of the camera body at an upper and lower left side portion of the mount member as viewed from the front of the camera body while the electrical contacts of the lens unit are located on the mount surface of the mount member of the lens unit at an upper and lower right side portion of the mount member as viewed from the rear of the lens unit with the mounting of the lens unit on the camera body completed. The electrical contacts of the lens unit are normally in a projecting state projecting slightly from the mount surface of the mount member of the lens unit respectively. Furthermore, with the camera, a driving shaft of the camera body to be coupled with a driven shaft of the lens unit for automatic focusing is located on the mount surface of the mount member of the camera body at an immediate left side portion of the mount member as viewed from the front of the camera body while the driven shaft is located on the mount surface of the mount member of the lens unit at an immediate right side portion of the mount member as viewed from the rear of the lens unit.
Other prior arts disclosing a mount arrangement which includes various means arranged on and/or in the vicinity of mount members of a camera body and an interchangeable lens unit for transmission of mechanical and electrical signals between the camera body and the interchangeable lens unit are U.S. Pat. Nos. 4,104,649, 4,432,627, 4,357,089 and 4,449,807, Japanese Patent laid open publication Nos. Sho. 58-83824 and Sho. 55-120022 and Japanese utility model laid open publication No. Sho. 56-60911.
Although many mount arrangements are known as described above, there is still a room for improvement in the arrangement of the various means on and/or in the vicinity of the mount members of the camera body and interchangeable lens unit, particularly when the camera is to be adapted to effect automatic diaphragm control and automatic focusing in accordance with signals from the camera body.